Rotary heat motor



Dec. 21, 1943. G. w. CRISE ROTARY HEATMOTOR Filed Aug. 2, 1194i) H oo INVE N TUR Patented Dec. 21, 1943 UNITED STATES PATENT OFFICE ROTARY HEATMOTOR George W. Crise, Mount Vernon, Ohio Application August 2, 1940,Serial No. 349,791

1 Claim.

The principal object oi my invention is to provide a simple andinexpensive slow speed motor for the operation of animated signsdirectly from the heat of the lamp used in lighting the sign.

Additional and important applications being the operation of displays,timers, switches, toys, water circulators and all other small powerapplications where it is desired to obtain slow speed motion from a heatsource.

Another object oi my invention is to provide a dependable power sourceby eliminating such trouble producing parts as windings, high speedbearings and gears, and at the same time produce a silent motor whosetorque increases as the motor is slowed down by any form of overlo-ad.

A further object of my invention is to produce a heat motor whosecommutation, or timing, is accomplished by carrying the propellin Telement through the heating zone by mounting it on a single rotatingmember which revolves through tw-o different temperature zones.

A siinpie embodiment of my invention uses a strip of thermostaticbimetal spirally coiled within a pivoted ring, the outer end oi thebimetal being attached te the ring and the inner end by a bearing to theoffset throw of a crank shaft, on the central end of which shaft thering rotates. A light bulb supplies heat to one side of the bimetal coilcausing it to distort throwing tension on the crank at right angles tothe heat source, resulting in rotation of the ring and bimetal spiralwhich carries other sections oi the bimetal into the heated zone withrecurring action and consequent continuous rotation.

The operation of my motor will be more clearly understood by referringto the accompanying drawing, in which i is a pivoted frame ring 1nsection, 2 a pivot hub member, shown in section, joined by the spokes 3,4, and 5 to ring l, and carrying hardened cup point set screw 6 to actas a pivot bearing.

l' is a crank shaft whose Central throw 1s pointed to carry bearing 6,and is supported by post 3 which in turn is manually rotatable 1n base9. tsl, il, and I2 are consecutive cous of a thin bimetal spiral, shownin section, which 1s fastened to frame ring I by rivet !3, and by rivetifi to a crank bearing l5. IS is a source of heat and light, Il is acombination reflector and heat bale.

IS is a transparent cylinder, shown 1n section, on which Iii, 2i?, and2l are irregular light varying and intercepting streaks.

22 is a screen on which are translucent designs 23, 24, and 25 so placedas to be in the path of light passing through cylinder I8. 26 is aknurled sleeve for rotating the crank 'I and post 8 in base S to controlthe motor speed and direction.

rom the foregoing it will be observed that the reflector baille I'Idivides the space within the cylinder I8 into two Zones, one of which isoccupied by the lamp i which when lighted causes a draft of hot air torise through the section of bimetal spiral I0, II, and I2 directly overit.

It will also be obvious that this rising hot air will induce a draft ofcool air through the opposite side of the same bimetal spiral Ill, I I,and I`2, by the well-known suction action of warm air currents inchimneys.

Now it is well known in the art that if a bimetal spiral be uniformlyheated or cooled, it will tend to wind or unwind concentrically becauseof the uniform bending action of all the bimetal, but if one side of thespiral be heated more than the other, the bending tendency will begreatest in the section of greatest temperature change, which willresult in the spiral becoming eccentric.

Since the bimetal spiral I0, II, and I2 is secured to ring I by rivetI3, the only way it can become eccentric is by moving the central turnof bimetal at I2, and since I`2 is attached to crank l by crank bearingI5 it will be obvious that pressure will be exerted on crank 'I atapproximate right angles to the heated section of bimetal I0, II, andI2, which is above lamp I6.

Since this pressure is out of line with the axis of rotation of ring I,which is free to rotate on the central point of crank shaft 'l at cupbearing 6, the entire motor and cylinder assembly will revolve, carryingthe already heated bimetal section away from lamp I5 and into the cooldraft rising on the opposite side of heat bailie I'I.

In this way a continually recurring distortion of the bimetal at rightangles to the heating Zone will hold pressure on crank I producingcontinuous rotation of the motor.

It will also be observed that by rotating post 8 by knurled sleeve 25,theposition of motor bearing 6 with respect to crank I and heat sourcecan be adjusted to any relation, thereby causing the bimetal distortionwhich is always at approximate right angles to the heating zone, toproduce rotation in either direction, or by adjusting it to a neutralposition, motor may be stopped. By adjusting the crank to various anglesbetween the neutral and maximum torque form of heat responsivedistorting member by revolving it through zones of diierent temperature.

What I claim is:

In combination a source of heat and a bimetal spiral rotatably mountedadjacent to said heat source, a stationary crank associated with saidbimetal whereby its bending action Will be transferred into torque whendifferent sections of said 10 bimetal are carried to and from said heatsource.

GEORGE W. CRISE.

